1. Field of the Invention
The present invention relates to spindle motors, and more particularly, to a spindle motor that improves the rotational characteristics of a rotor when a stator and a rotor are coupled with each other.
2. Description of the Related Art
In general, a spindle motor, installed inside a hard disk drive, rotates a disk so that a magnetic head can read data recorded on the disk.
Small, lightweight, and thin hard disk drives are now required. In particular, there is an increasing need for ultra-thin, slim spindle motors having a spindle structure, used in laptop computers, which can maintain the performance of a motor and at the same time, increase price competitiveness.
This spindle motor may include a shaft that serves as the rotary center rotating by hydrodynamic bearings and a metal sleeve assembled with the shaft to form a sliding surface.
The spindle motor in the related art is configured so that a magnetic field is generated in the axial direction of the bearings. To this end, a pulling plate may be arranged under a magnet at a position corresponding to the magnet.
However, as for the spindle motor in the related art, the pulling plate may be inappropriately bonded to a base if an adhesive is unevenly applied in a process of bonding the pulling plate to the base. Therefore, there is a need for techniques to solve these problems.